All three Democratic presidential candidates are considered top-tier. According to the RealClearPolitics national average of polling, Biden leads among Democratic voters with 29.2%, Warren comes in second place with 23.4%, while Sanders has fallen to third with 15.2% of the vote.

In a distant fourth and fifth Place are South Bend, Indiana, Mayor Pete Buttigieg and Sen. Kamala Harris (D-CA) with 5.8% and 5.4%, respectively.

Looking at the early primary/caucus states, Trump appears to be remaining competitive — though it must be noted that there are many fewer state polls than national polls, so the numbers are likely less stable and reliable.

In Iowa, Trump leads Biden 51% to 49% according to the latest poll from Emerson. While the president holds the same lead over Warren, the roles are switched when Sanders enters the picture. According to Emerson, Sanders commands 51% to Trump’s 49% in Iowa.

In North Carolina, a state Trump won by 3.6% in 2016, the margins are larger but still somewhat competitive. The RCP average has the president losing to Biden 51.5% to 44.3%, losing to Warren 47.8% to 47%, and losing to Sanders 50% to 46%. Only against lower-tier candidates like Harris and Buttigieg does Trump eke out a win in North Carolina.

In Wisconsin, a state Trump won by just 0.7% in 2016, the polls are looking grim for the president. The RCP average has Trump losing to Biden 49.5% to 40.5%, losing to Warren 45% to 43%, and losing to Sanders 46.5% to 42%.

National poll averages show all three frontrunner Democrats beating Trump by a minimum of 5%. The RCP average has Trump losing to Biden 49.9% to 43%, losing to Warren 49% to 43.8%, and losing to Sanders 49.3% to 44%.

While it must be noted that polling is a snapshot in time of a particular (if representative) sample of Americans, Trump’s standing, especially in state polls, can be instructive.

It’s possible that the ongoing talk of impeachment could be making an impact on the president’s popularity, and boosting the prospects of his rivals. According to a Gallup survey released on Wednesday, 52% of Americans want the president “impeached and removed from office,” which represents a 7% swing from a survey in June when only 45% said the same.